Scientific Calculator

/* involves exclusively outline functions
1.Passing of values from the main function to the sub function
and calling of the function

*/


#include <iostream>
#include <conio.h>
#include <math.h>

using namespace std;
double cores (double);
double res (double);

float sub(float ,float);
float div(float,float);
float mul(float,float);
float add(float,float);
float ramp(float,float);
double modulus_(double);
void menu();

float a,b,c,ch;
int ch1;

int main()
{
 system("cls");

  menu();

  cin >> ch;
 if (ch == 1)
 {
  c = mul(a, b);
  cout << "the multilication result is" << c;
 }
 else if (ch == 2)
 {
  c = add(a, b);
  cout << "the result is" << c;
 }
 else if (ch == 3)
 {
  c = sub(a, b);
  cout << "the result is" << c;
 }
 else if (ch == 4)
 {
  c = div(a, b);
  cout << "the result is " << c;
 }
 else if (ch == 5)
 {
  cout << "the power is";
  c = ramp(a, b);
  cout << "the result is" << c;
 }
 else if (ch == 6)
 {
  cout << "the modulus o9f the no. is" << endl;
  c = modulus_(a);
  cout << c;
 }
 else if (ch == 7)
 {
  cout << "the cos value is" << endl;
  c = cores(a);
  cout << c;
 }
 else if (ch == 8)
 {
  cout << "the sin value is" << endl;
  c = res(a);
  cout << c;
 }
 else
 {
  cout << "out of credentials sorry";
 }

  system("pause");

  return 0;
}



float mul(float x, float y)
{
 float res;

  res = x*y;

  return (res);
}

float add(float x, float y)
{
 float res;

  res = x + y;

  return (res);
}

float sub(float x, float y)
{
 float res;

  res = x - y;
 return (res);
}

float div(float x, float y)
{
 float res;

  res = x / y;

  return (res);
}

float ramp(float x, float y)
{
 float i, s = 1;
 for (i = 1; i <= y; i++)
 {
  s = s*x;
 }

  return (s);
}

double modulus_(double x)
{
 double res;

  res = fabs(x);

  return (res);
}
void menu()
{
 cout << "=======PROGRAM FOR SCIENTIFIC CALCULATOR=======" << endl;
 cout << "enter the variabes" << endl;

  cout << "eneter a:" ;

  cout << "enter b: " ;
 cin>>a;
 cin >> b;



  cout << "enter the function which you want to perform" << endl;

  cout << "1.mult" << endl << "2.add" << endl << "3.sub" << endl << "4.div" << endl << "5.pow" << endl << "6.modulus" << endl;
 cout << "7.cos(0,30,60,90,45,37,53)" << endl << "8.sin(0,30,45,60,90,37,53)" << endl;

}

double cores(double ang)
{
 double result = 0;
 if (ang == 45)
 {
  a = b = 1;
  c = a*a + b*b;
  cout << "the cos value of 45 deg is" << endl;
  result = (b / sqrt(c));


  }
 else if (ang == 60)
 {
  b = 1, c = 2;
  c = 2 * b;
  a = ((c*c) - (b*b));


   cout << "the cos value is" << result;
 }
 else if (ang == 30)
 {
  b = 1, c = 2;
  c = 2 * b;
  a = ((c*c) - (b*b));

   result = (sqrt(a) / c);



  }
 else if (ang == 90)
 {
  result = 1;

   cout << "cos value is ";
 }
 else if (ang == 37)
 {
  a = 3, b = 4;
  c = ((a*a) + (b*b));
  result = b / sqrt(c);

   cout << "the cos value of 37 is ";
 }
 else if (ang == 53)
 {
  a = 4, b = 3;
  c = ((a*a) + (b*b));
  result = a / sqrt(c);

   cout << "the cos value of 53 is ";
 }
 else if (ang == 0)
 {
  result == 1;

   cout << "the cos value is";
 }
 else
 {
  cout << "sorry out of the given credentials";
 }



  //getch();

  return (result);
}

double res(double ang)
{
 double result = 0;

  if (ang == 45)
 {
  a = b = 1;
  c = a*a + b*b;
  cout << "the cos value of 45 deg is" << endl;
  result = (b / sqrt(c));
  cout << result;
 }
 else if (ang == 60)
 {
  b = 1, c = 2;
  c = 2 * b;
  a = ((c*c) - (b*b));


   result = (sqrt(a) / c);
  cout << "\n" << "the sin value is" << result;
 }
 else if (ang == 30)
 {
  b = 1, c = 2;
  c = 2 * b;
  a = ((c*c) - (b*b));


   result = (b / c);
  cout << "\n" << "the sin value is" << result;

  }
 else if (ang == 90)
 {

   result = 0;
  cout << "\n" << "the value of sin wll be" << result;
 }
 else if (ang == 37)
 {
  a = 3, b = 4;
  c = ((a*a) + (b*b));

   result = a / sqrt(c);
  cout << "\n" << "the sin value of 37 is" << result;
 }
 else if (ang == 53)
 {
  a = 4, b = 3;
  c = ((a*a) + (b*b));

   result = b / sqrt(c);
  cout << "\n" << "the sin value of 53 is" << result;
 }
 else if (ang == 0)
 {

   result == 0;
  cout << "\n" << "the sin value is " << result;
 }
 else
 {
  cout << "sorry out of the given credentials";
 }

  //getch();

  return (result);
}